The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Mar. 06, 2007
Filed:
Aug. 29, 2003
Masahiro Kato, Tokorozawa, JP;
Tatsuhiro Yone, Tokorozawa, JP;
Shigeru Yoshida, Tokorozawa, JP;
Kanji Ishihara, Tokorozawa, JP;
Masahiro Kato, Tokorozawa, JP;
Tatsuhiro Yone, Tokorozawa, JP;
Shigeru Yoshida, Tokorozawa, JP;
Kanji Ishihara, Tokorozawa, JP;
Pioneer Corporation, Tokyo-To, JP;
Abstract
A tilt of a light beam to be radiated onto an information recording disk is corrected without using a dedicated tilt sensor. The correction is performed based on the characteristic that an offset amount between a tilt amount maximizing an RF signal amplitude and a further tilt amount maximizing an LPP signal amplitude is constant and independent of positions on the same disk. A pre-pit signal indicative of an existence/nonexistence of a pre-pit formed on the disk is produced from returned light of the light beam, while an RF signal is produced from bits of information recorded on the disk on the basis of the returned light. An optimum tilt-correcting amount is decided by making use of a relationship between the pre-pit signal and the RF signal at a particular tilt amount. The tilt amount is corrected using the optimum tilt-correcting amount.